Doing a few required changes swiftly and then porting the remaining tests bit by bit sounds like an approachable plan. However, it will still cost us some effort I guess. What exactly would be the benefit of this change other than streamlining a few things? Are there things which we cannot do at the moment but which would be possible with Junit5?
Don't get me wrong, personally I also would like to use the latest Junit version with the cool new features available. However, at the end of the day, we only have limited time and should choose wisely where we invest it. For example, currently I consider the state of the e2e tests much more severe and would like to clean this one up first. If you believe that the community can do both things, then I am fine with it. Maybe the answer could be that we will never port all existing tests but we offer the opportunity to write new tests against Junit5. Or maybe porting the existing tests is so simple that it can be done by a couple of persons in one go. Cheers, Till On Mon, Nov 30, 2020 at 1:51 PM Arvid Heise <ar...@ververica.com> wrote: > Hi Chesnay, > > The vintage runner supports the old annotations, so we don't have to change > them in the first step. > > The only thing that we need to change are all rules that do not extend > ExternalResource (e.g., TestWatcher used in TestLogger). This change needs > to be done swiftly as this affects the shared infrastructure as you have > mentioned. > > Only afterwards, we start to actually migrate the individual tests. That > can be done module by module or as we go. I actually found a nice article > that leverages the migration assist of IntelliJ [1]. > > As the last stop, we remove the vintage runner - all JUnit4 tests have been > migrated and new tests cannot use old annotation etc. anymore. > > [1] > https://blog.jetbrains.com/idea/2020/08/migrating-from-junit-4-to-junit-5/ > > On Mon, Nov 30, 2020 at 1:32 PM Chesnay Schepler <ches...@apache.org> > wrote: > > > I presume we cannot do the migration module-wise due to shared test > > utilities that rely on JUnit interfaces? > > > > On 11/30/2020 1:30 PM, Chesnay Schepler wrote: > > > Is it feasible that 2 people can do the migration within a short > > > time-frame (say, a week)? > > > Must the migration of a test be done in one go, or can we for example > > > first rename all the Before/After annotations and then to the rest? > > > Are there any issues with other test dependencies (i.e., hamcrest, > > > powermock (PowerMockRunner), mockito) that we should be aware of? > > > > > > I generally like the idea of using JUnit 5, but am wary of this > > > migration dragging on for too long. > > > > > > On 11/27/2020 3:29 PM, Arvid Heise wrote: > > >> Dear devs, > > >> > > >> I'd like to start a discussion to migrate to a higher JUnit version. > > >> > > >> The main motivations are: > > >> - Making full use of Java 8 Lambdas for writing easier to read tests > > >> and a > > >> better performing way of composing failure messages. > > >> - Improved test structures with nested and dynamic tests. > > >> - Much better support for parameterized tests to avoid separating > > >> parameterized and non-parameterized parts into different test classes. > > >> - Composable dependencies and better hooks for advanced use cases > > >> (TestLogger). > > >> - Better exception verification > > >> - More current infrastructure > > >> - Better parallelizable > > >> > > >> Why now? > > >> - JUnit5 is now mature enough to consider it for such a complex > project > > >> - We are porting more and more e2e tests to JUnit and it would be a > > >> pity to > > >> do all the work twice (okay some already has been done and would > > >> result in > > >> adjustments, but the sooner we migrate, the less needs to be touched > > >> twice) > > >> > > >> Why JUnit5? > > >> There are other interesting alternatives, such as TestNG. I'm happy > > >> to hear > > >> specific alternatives. For now, I'd like to focus on JUnit4 for an > > >> easier > > >> migration path. > > >> > > >> Please discuss if you would also be interested in moving onward. To > get > > >> some overview, I'd like to see some informal +1 for the options: > > >> > > >> [ ] Stick to JUnit4 for the time being > > >> [ ] Move to JUnit5 (see migration path below) > > >> [ ] Alternative idea + advantages over JUnit5 + some very rough > > >> migration > > >> path > > >> > > >> --- > > >> > > >> Migrating from JUnit4 to JUnit5 can be done in some steps, so that we > > >> can > > >> gradually move from JUnit4 to JUnit5. > > >> > > >> 0. (There is a way to use JUnit4 + 5 at the same time in a project - > > >> you'd > > >> use a specific JUnit4 runner to execute JUnit5. I'd like to skip this > > >> step > > >> as it would slow down migration significantly) > > >> 1. Use JUnit5 with vintage runner. JUnit4 tests run mostly out of the > > >> box. > > >> The most important difference is that only 3 base rules are supported > > >> and > > >> the remainder needs to be migrated. Luckily, most of our rules derive > > >> from > > >> the supported ExternalResource. So in this step, we would need to > > >> migrate > > >> the rules. > > >> 2. Implement new tests in JUnit5. > > >> 3. Soft-migrate old tests in JUnit5. This is mostly a renaming of > > >> annotation (@Before -> @BeforeEach, etc.). Adjust parameterized tests > > >> (~400), replace rule usages (~670) with extensions, exception handling > > >> (~1600 tests), and timeouts (~200). This can be done on a test class > by > > >> test class base and there is no hurry. > > >> 4. Remove vintage runner, once most tests are migrated by doing a > final > > >> push for lesser used modules. > > >> > > >> Let me know what you think and I'm happy to answer all questions. > > >> > > > > > > > > > > > > -- > > Arvid Heise | Senior Java Developer > > <https://www.ververica.com/> > > Follow us @VervericaData > > -- > > Join Flink Forward <https://flink-forward.org/> - The Apache Flink > Conference > > Stream Processing | Event Driven | Real Time > > -- > > Ververica GmbH | Invalidenstrasse 115, 10115 Berlin, Germany > > -- > Ververica GmbH > Registered at Amtsgericht Charlottenburg: HRB 158244 B > Managing Directors: Timothy Alexander Steinert, Yip Park Tung Jason, Ji > (Toni) Cheng >
